Powertrain, generic (extended)

P2845 Shift Fork A Position Sensor Incorrect Neutral Position Indicated

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2845 means the fork A sensor reports neutral although the gearbox state says a gear is engaged, or it reports an engaged position where neutral is expected. Public manufacturer documentation for P2845 is lacking, and CARB 13 CCR 1968.2 only asks that transmission inputs be checked for plausibility. How such a check works is visible in GM's 2023 Corvette dual-clutch table: the module learns neutral and engaged positions for every rod and, with no shift force applied, expects the reading to stay inside tolerance bands around them, but it stores deviations under other codes. A shifted sensor magnet, a worn fork or lost learned values after a repair are likely triggers; a relearn with a scan tool is the first step, followed by a mechanical check.

Likely causes

Neutral position not learned or lost after repair or software update
Sensor magnet or target shifted on the rod
Worn fork or detent changing the neutral position

Symptoms

  • Gear display shows N while a gear is engaged, or the reverse
  • Shifts refused, transmission in limp-home mode
  • Warning lamp on

Repair estimate

DifficultyHardWorkshop job
Parts and labour€80–2,500
Time0.5–8 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

shift fork position sensor ashift fork atcm

Related codes

P2832P2831P2846P2849P284D

References: law.cornell.edu, gsi.ext.gm.com.